In other words, is it possible that during the actual gunfight there was not an effect of tunnel vision?

Possible but not likely. I believe this because at times I have noted myself experiencing it, it did not go away right away. I had to make conscious physical efforts to dismiss the effect.

__________________Tomorrow is the most important thing in life. Comes into us at midnight very clean. It's perfect when it arrives and it puts itself in our hands. It hopes we've learned something from yesterday.